Title: Investigation of EMI shielding effectiveness of a novel highly flexible SWCNT or EMA nanocomposite at a very low percolation threshold

Abstract

The rising trend of electromagnetic pollution has motivated us to develop a novel electromagnetic interference shielding (EMI) material by adopting a facile, industry viable, and cost-effective solution mixing strategy. Single-walled carbon nanotubes (SWCNT) as conductive fillers is employed in a lightweight, highly flexible ethylene methyl acrylate (EMA) polymer to fabricate the superior electrically conductive and efficient EMI shielding material at a relatively lower percolation threshold limit compared to other carbonaceous fillers. The morphological characterization of the fabricated nanocomposite, using field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) reveals excellent degree of distribution and dispersion of CNTs, respectively, justifying the efficacy of the adopted processing method. The mechanical properties characterization is done through tensile testing, revealing the increment of strength and stiffness with CNT loadings, and however retaining the high flexibility of the nanocomposites. The investigation of DC and AC electrical conductivity displays considerable improvements with very low amount of conductive filler loading. The EMI shielding efficiency increases monotonically with the addition of SWCNTs and the electrical conductive network formation is attained at just 1.96wt% of SWCNT loading resulting in more than 20 dB of EMI shielding effectiveness (EMI SE) dominated by absorption mechanism to fulfill the industrial requirement along with excellent mechanical properties improvement, and the highest SE is 45 dB at 15wt% of reinforcement facilitating their potential use in both industry and academia.